This invention relates to trailer and truck combinations, and in particular, to a tow bar lift mechanism for a trailer employed in a palletized load system. While the invention is described with particularity in connection with a military palletized load system trailer, those skilled in the art will recognize the wider applicability of the inventive principles disclosed hereinafter.
Palletized load systems (PLS) have become accepted transportation systems in a wide variety of applications. In general, PLS systems include a truck, a trailer, and flat racks designed to be on-loaded and off-loaded on both the truck and the trailer. The trailer in the combination, is carried behind the truck in a tandem operation through a tow bar. PLS systems provide efficient methods to distribute supplies and equipment which are carried on or by a flat rack.
In operational use, the trailer often is disconnected from the truck while the equipment carried by the trailer is off-loaded. Thereafter, the trailer must be reconnected to the truck in order to move it to the next location. In military applications of palletized load systems, both the truck and trailer are designed to carry heavy loads over rough terrain. Consequently, the components, including the trailer tow bar are sturdy and heavy. It is often difficult in the field to reattach the tow bar to the truck when movement of the trailer is desired. While there have been a number of power assisted mechanisms available in the past, they all suffer from certain deficiencies. Because of the rough terrain over which the truck must pass, the tow bar must be able to operate over a wide range, in both the vertical and horizontal plane. Power assist mechanisms in the past, which have been interconnected to the tow bar, have restricted this operational movement. Even when the power assist is capable of disconnection from the tow bar, the mechanisms have been complicated and expensive.
One of the objects of this invention is to provide a simplified and economical power assist device for attaching a tow bar to a truck.
Another object of this invention is to provide a tow bar lift mechanism which will enable operators of widely varying strength to raise the tow bar a sufficient height to attach the tow bar to a truck.
Another object of this invention is to provide a tow bar lift mechanism that is independent of the tow bar permitting the tow bar movement over its normal operating range.
Another object of this invention is to provide a tow bar lift mechanism which is powered from a power source available on the truck or trailer or both.
Other objects will be apparent to those skilled in the art in view of the following disclosure and accompanying drawings